The present invention relates to rotary tableting machines, and more particularly to a rotary tableting machine equipped with a covering for enclosing the turntable and the like of the machine to introduce clean air into the interior of the covering and to thereby collect the powder scattered in the interior.
Generally when the rotary tableting machine is operated, the powder is fed by a hopper onto a turntable rotating at a high speed and is placed into dies in the turntable by a feeder. Upper and lower punches operate to compress the powder in the dies, and the molded tablets are pushed upward out of the dies by the lower punches thereafter raised and are then discharged via a chute.
The tableting operation usually entails the problem that the powder scattered or strewn in the air accumulates in the interior of the machine, causing various troubles, and stain the room.
In view of the recent attempts made by various countries to set up standards for the production and quality control of pharmaceuticals, the above-mentioned problem of the powder scattered in the air is most serious.
In order to overcome this problem, it has been chiefly practiced to introduce clean air into the interior of a covering enclosing the whole tableting machine or to collect the powder in the inside of the covering. However, the former method has the fatal drawback that the scattered powder accumulates in internal portions of the machine, whereas with the latter method the rate of collection of the powder is invariably lower than the speed of rotation of the turntable, permitting a large amount of powder to remain in the interior of the machine.